Maybe related, the big vacuum tower contains 10 tons or Mercury.
"The rotating part of the telescope weighs more than 200 tons. It is suspended at the top from a ring- shaped container holding 10 tons of mercury. The central tube is hanging: it does not sit on anything. Because mercury has very low friction, it is fairly easy to rotate the 200 tons of tube and instruments."
I remember to have red somewhere that secret technologies involved mercury (antigravity / free energy or something related) Nazis had a project named "Die Glocke" involving Mercury also.
https://en.wikipedia.org/wiki/Die_Glocke
Search also abbout mercury vortex engine, many interesting things.
"Die Glocke" is certainly inspired of old Indians legends about "Vimana". The supposed shape of "die Glocke" is very closed to the descriptions of Vimanas. Knowing that Nazis sent scientists all around the world to study old writings, it may be related.
It may be also pure legend But..?